>>86690735Console and arcade games were perfectly mainstream in Japan in the 80s. Computers games not so much (which is still true today). Visual novels/dating sims have probably received more adaptations than regular games, but both continue to be adapted to this day. Tales of Zestiria's adaptation is on-going, and before that there were God Eater and Gunslinger Stratos among others. Mobile games are also adapted often now (Granblue Fantasy is coming soon for example).
It's part of the media mix strategy. You turn your game into an anime and your anime into a game, or make both at once. A really media mixed series can have a manga, anime, game, audio drama, live action show/movie and a stage play.
Everyone reads manga too but there's still shit-tons of anime adaptations of it.